Combined flow control and interference cancellation for packet data transmission in wideband CDMA systems

We consider packet scheduling and rate assignment on the uplink of a packet data wireless CDMA network in the presence of imperfect interference cancellation (IC) and limited user transmission rates, and subject to in-cell and out-of-cell resource limitations. The objective is to propose and implement a system level position-based flow control algorithm that accounts for a limited IC capability provided by power control for multi-user detection. The proposed algorithm assigns packets to be transmitted to separate queues, one for each spatial zone within which packets generate roughly the same in-cell interference and impose equal interference on a neighboring base station. Given the cell partitioning into zones, the algorithm dynamically adapts to the resource constraints and efficiently uses IC to provide for fairness in serving the various queues without giving up the objective of maximizing data throughput. Throughput and fairness are two conflicting objectives to be optimized. We show that the joint use of IC and location-based scheduling is able to achieve complete fairness with negligible loss in throughput even under stringent resource limitations.